riscv: entry: Consolidate general regs saving/restoring

Consolidate the saving/restoring GPs (except zero, ra, sp, gp,
tp and t0) into save_from_x6_to_x31/restore_from_x6_to_x31 macros.

No functional change intended.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230222033021.983168-8-guoren@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/include/asm/asm.h

@@ -69,6 +69,7 @@
 #endif
 
 #ifdef __ASSEMBLY__
+#include <asm/asm-offsets.h>
 
 /* Common assembly source macros */
 
@@ -81,6 +82,66 @@
 	.endr
 .endm
 
+	/* save all GPs except x1 ~ x5 */
+	.macro save_from_x6_to_x31
+	REG_S x6,  PT_T1(sp)
+	REG_S x7,  PT_T2(sp)
+	REG_S x8,  PT_S0(sp)
+	REG_S x9,  PT_S1(sp)
+	REG_S x10, PT_A0(sp)
+	REG_S x11, PT_A1(sp)
+	REG_S x12, PT_A2(sp)
+	REG_S x13, PT_A3(sp)
+	REG_S x14, PT_A4(sp)
+	REG_S x15, PT_A5(sp)
+	REG_S x16, PT_A6(sp)
+	REG_S x17, PT_A7(sp)
+	REG_S x18, PT_S2(sp)
+	REG_S x19, PT_S3(sp)
+	REG_S x20, PT_S4(sp)
+	REG_S x21, PT_S5(sp)
+	REG_S x22, PT_S6(sp)
+	REG_S x23, PT_S7(sp)
+	REG_S x24, PT_S8(sp)
+	REG_S x25, PT_S9(sp)
+	REG_S x26, PT_S10(sp)
+	REG_S x27, PT_S11(sp)
+	REG_S x28, PT_T3(sp)
+	REG_S x29, PT_T4(sp)
+	REG_S x30, PT_T5(sp)
+	REG_S x31, PT_T6(sp)
+	.endm
+
+	/* restore all GPs except x1 ~ x5 */
+	.macro restore_from_x6_to_x31
+	REG_L x6,  PT_T1(sp)
+	REG_L x7,  PT_T2(sp)
+	REG_L x8,  PT_S0(sp)
+	REG_L x9,  PT_S1(sp)
+	REG_L x10, PT_A0(sp)
+	REG_L x11, PT_A1(sp)
+	REG_L x12, PT_A2(sp)
+	REG_L x13, PT_A3(sp)
+	REG_L x14, PT_A4(sp)
+	REG_L x15, PT_A5(sp)
+	REG_L x16, PT_A6(sp)
+	REG_L x17, PT_A7(sp)
+	REG_L x18, PT_S2(sp)
+	REG_L x19, PT_S3(sp)
+	REG_L x20, PT_S4(sp)
+	REG_L x21, PT_S5(sp)
+	REG_L x22, PT_S6(sp)
+	REG_L x23, PT_S7(sp)
+	REG_L x24, PT_S8(sp)
+	REG_L x25, PT_S9(sp)
+	REG_L x26, PT_S10(sp)
+	REG_L x27, PT_S11(sp)
+	REG_L x28, PT_T3(sp)
+	REG_L x29, PT_T4(sp)
+	REG_L x30, PT_T5(sp)
+	REG_L x31, PT_T6(sp)
+	.endm
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_RISCV_ASM_H */

arch/riscv/kernel/entry.S

@@ -42,32 +42,7 @@ _save_context:
 	REG_S x1,  PT_RA(sp)
 	REG_S x3,  PT_GP(sp)
 	REG_S x5,  PT_T0(sp)
-	REG_S x6,  PT_T1(sp)
-	REG_S x7,  PT_T2(sp)
-	REG_S x8,  PT_S0(sp)
-	REG_S x9,  PT_S1(sp)
-	REG_S x10, PT_A0(sp)
-	REG_S x11, PT_A1(sp)
-	REG_S x12, PT_A2(sp)
-	REG_S x13, PT_A3(sp)
-	REG_S x14, PT_A4(sp)
-	REG_S x15, PT_A5(sp)
-	REG_S x16, PT_A6(sp)
-	REG_S x17, PT_A7(sp)
-	REG_S x18, PT_S2(sp)
-	REG_S x19, PT_S3(sp)
-	REG_S x20, PT_S4(sp)
-	REG_S x21, PT_S5(sp)
-	REG_S x22, PT_S6(sp)
-	REG_S x23, PT_S7(sp)
-	REG_S x24, PT_S8(sp)
-	REG_S x25, PT_S9(sp)
-	REG_S x26, PT_S10(sp)
-	REG_S x27, PT_S11(sp)
-	REG_S x28, PT_T3(sp)
-	REG_S x29, PT_T4(sp)
-	REG_S x30, PT_T5(sp)
-	REG_S x31, PT_T6(sp)
+	save_from_x6_to_x31
 
 	/*
 	 * Disable user-mode memory access as it should only be set in the
@@ -182,32 +157,7 @@ SYM_CODE_START_NOALIGN(ret_from_exception)
 	REG_L x3,  PT_GP(sp)
 	REG_L x4,  PT_TP(sp)
 	REG_L x5,  PT_T0(sp)
-	REG_L x6,  PT_T1(sp)
-	REG_L x7,  PT_T2(sp)
-	REG_L x8,  PT_S0(sp)
-	REG_L x9,  PT_S1(sp)
-	REG_L x10, PT_A0(sp)
-	REG_L x11, PT_A1(sp)
-	REG_L x12, PT_A2(sp)
-	REG_L x13, PT_A3(sp)
-	REG_L x14, PT_A4(sp)
-	REG_L x15, PT_A5(sp)
-	REG_L x16, PT_A6(sp)
-	REG_L x17, PT_A7(sp)
-	REG_L x18, PT_S2(sp)
-	REG_L x19, PT_S3(sp)
-	REG_L x20, PT_S4(sp)
-	REG_L x21, PT_S5(sp)
-	REG_L x22, PT_S6(sp)
-	REG_L x23, PT_S7(sp)
-	REG_L x24, PT_S8(sp)
-	REG_L x25, PT_S9(sp)
-	REG_L x26, PT_S10(sp)
-	REG_L x27, PT_S11(sp)
-	REG_L x28, PT_T3(sp)
-	REG_L x29, PT_T4(sp)
-	REG_L x30, PT_T5(sp)
-	REG_L x31, PT_T6(sp)
+	restore_from_x6_to_x31
 
 	REG_L x2,  PT_SP(sp)
 
@@ -287,32 +237,7 @@ restore_caller_reg:
 	REG_S x1,  PT_RA(sp)
 	REG_S x3,  PT_GP(sp)
 	REG_S x5,  PT_T0(sp)
-	REG_S x6,  PT_T1(sp)
-	REG_S x7,  PT_T2(sp)
-	REG_S x8,  PT_S0(sp)
-	REG_S x9,  PT_S1(sp)
-	REG_S x10, PT_A0(sp)
-	REG_S x11, PT_A1(sp)
-	REG_S x12, PT_A2(sp)
-	REG_S x13, PT_A3(sp)
-	REG_S x14, PT_A4(sp)
-	REG_S x15, PT_A5(sp)
-	REG_S x16, PT_A6(sp)
-	REG_S x17, PT_A7(sp)
-	REG_S x18, PT_S2(sp)
-	REG_S x19, PT_S3(sp)
-	REG_S x20, PT_S4(sp)
-	REG_S x21, PT_S5(sp)
-	REG_S x22, PT_S6(sp)
-	REG_S x23, PT_S7(sp)
-	REG_S x24, PT_S8(sp)
-	REG_S x25, PT_S9(sp)
-	REG_S x26, PT_S10(sp)
-	REG_S x27, PT_S11(sp)
-	REG_S x28, PT_T3(sp)
-	REG_S x29, PT_T4(sp)
-	REG_S x30, PT_T5(sp)
-	REG_S x31, PT_T6(sp)
+	save_from_x6_to_x31
 
 	REG_L s0, TASK_TI_KERNEL_SP(tp)
 	csrr s1, CSR_STATUS

arch/riscv/kernel/mcount-dyn.S

@@ -66,66 +66,17 @@
 	REG_S x3,  PT_GP(sp)
 	REG_S x4,  PT_TP(sp)
 	REG_S x5,  PT_T0(sp)
-	REG_S x6,  PT_T1(sp)
-	REG_S x7,  PT_T2(sp)
-	REG_S x8,  PT_S0(sp)
-	REG_S x9,  PT_S1(sp)
-	REG_S x10, PT_A0(sp)
-	REG_S x11, PT_A1(sp)
-	REG_S x12, PT_A2(sp)
-	REG_S x13, PT_A3(sp)
-	REG_S x14, PT_A4(sp)
-	REG_S x15, PT_A5(sp)
-	REG_S x16, PT_A6(sp)
-	REG_S x17, PT_A7(sp)
-	REG_S x18, PT_S2(sp)
-	REG_S x19, PT_S3(sp)
-	REG_S x20, PT_S4(sp)
-	REG_S x21, PT_S5(sp)
-	REG_S x22, PT_S6(sp)
-	REG_S x23, PT_S7(sp)
-	REG_S x24, PT_S8(sp)
-	REG_S x25, PT_S9(sp)
-	REG_S x26, PT_S10(sp)
-	REG_S x27, PT_S11(sp)
-	REG_S x28, PT_T3(sp)
-	REG_S x29, PT_T4(sp)
-	REG_S x30, PT_T5(sp)
-	REG_S x31, PT_T6(sp)
+	save_from_x6_to_x31
 	.endm
 
 	.macro RESTORE_ALL
-	REG_L t0,  PT_EPC(sp)
 	REG_L x1,  PT_RA(sp)
 	REG_L x2,  PT_SP(sp)
 	REG_L x3,  PT_GP(sp)
 	REG_L x4,  PT_TP(sp)
-	REG_L x6,  PT_T1(sp)
-	REG_L x7,  PT_T2(sp)
-	REG_L x8,  PT_S0(sp)
-	REG_L x9,  PT_S1(sp)
-	REG_L x10, PT_A0(sp)
-	REG_L x11, PT_A1(sp)
-	REG_L x12, PT_A2(sp)
-	REG_L x13, PT_A3(sp)
-	REG_L x14, PT_A4(sp)
-	REG_L x15, PT_A5(sp)
-	REG_L x16, PT_A6(sp)
-	REG_L x17, PT_A7(sp)
-	REG_L x18, PT_S2(sp)
-	REG_L x19, PT_S3(sp)
-	REG_L x20, PT_S4(sp)
-	REG_L x21, PT_S5(sp)
-	REG_L x22, PT_S6(sp)
-	REG_L x23, PT_S7(sp)
-	REG_L x24, PT_S8(sp)
-	REG_L x25, PT_S9(sp)
-	REG_L x26, PT_S10(sp)
-	REG_L x27, PT_S11(sp)
-	REG_L x28, PT_T3(sp)
-	REG_L x29, PT_T4(sp)
-	REG_L x30, PT_T5(sp)
-	REG_L x31, PT_T6(sp)
+	/* Restore t0 with PT_EPC */
+	REG_L x5,  PT_EPC(sp)
+	restore_from_x6_to_x31
 
 	addi	sp, sp, PT_SIZE_ON_STACK
 	.endm